Magnetic dental appliances and methods for using same

ABSTRACT

Magnetic dental appliances and materials therefor, magnetic denture teeth, magnetic transfer apparatus and method magnetic denture material; and particularly magnetic methods and apparatus for making full dentures and bridges providing an accurate functional balance of occlusion and centric relation for use in the full denture and bridge construction, including the use of magnetic holding means for transferring the upper baseplate and lower bite rim in proper locked relationship to an articulator. Also, a method of retention of the dentures and bridges in place in the mouth during use by magnetic means is provided, including magnetic core artificial teeth, magnetic denture base material, and magnetic alloy inserts for implanting under the soft tissue along and into the alveolar ridge.

United States Patent [151 3,646,676 Mitchell [451 Mar. 1, 1972 [54]MAGNETIC DENTAL APPLIANCES AND METHODS FOR USING SAME [72] Inventor:John Pat 1 Mitchell, 3301 Greenville Avenue, Dallas, Tex. 75206 [22]Filed: Feb. 24, 1970 [211 App]. No.: 13,548

[52] US. CL ..32/2 [51] Int. (I A61: 13/00 [58] Field ofSearch ..32/32,19, 2, DIG. 6

[56] References Cited UNITED STATES PATENTS 2,709,301 5/1955 Goldsmith..32/2 3 ,5 14,859 6/ l 970 Peterson ..32/2 2,884,696 5/1959 Bonfanti32/DIG. 6 2,245,288 6/1941 Moylan ..32/19 Primary Examiner-RobertPeshock Attorney-E. Hastings Ackley [57] ABSTRACT Magnetic dentalappliances and materials therefor, magnetic denture teeth, magnetictransfer apparatus and method magnetic denture material; andparticularly magnetic methods and apparatus for making full dentures andbridges providing an accurate functional balance of occlusion andcentric relation for use in the full denture and bridge construction,including the use of magnetic holding means for transferring the upperbaseplate and lower bite rim in proper locked relationship to anarticulator. Also, a method of retention of the dentures and bridges inplace in the mouth during use by magnetic means is provided, includingmagnetic core artificial teeth, magnetic denture base material, andmagnetic alloy inserts for implanting under the soft tissue along andinto the alveolar ridge.

5 Claims, 10 Drawing figures PAIENTEBMAR 7:972 3,646,676

sum 2 [1F 2 INVE R John PMiTc I ATTORNEY MAGNETIC DENTAL APPLIANCES ANDMETHODS FOR USING SAME SUBJECT MA'I'IER AND OBJECTS OF THE INVENTION Theinvention relates to magnetic alloy dental materials and to the methodsof using.the same, more particularly in the construction of fulldentures, partial dentures, and both removable and stationary bridges.

It is one object of the invention to provide an improved method of andapparatus for making and transferring upper baseplate and lower bite rimwithout tipping, twisting, unequal pressures, or sticking togethercommon to present methods; also to provide a magnetic method andapparatus for determining the centric relation of the mandible andmaxilla and to I reduce absorption of the users bone, structure by acorrect balance and correct vertical dimension at the even centricrelationship.

A further object of the invention is to provide an improved accuratefast method and means for locking the upper baseplate and lower bite rimused in forming full dentures in proper centric and occlusalrelationship during transfer from the patients mouth to an articulator,including the use of magnetic holding means secured to the lower biterim and upper baseplate for holding them in fixed position afterdetermina tion of the centric occlusal relationship.

A still further object of the invention is to provide magnetic means forcarrying out the method of determining the centric and occlusalrelationship in the patients mouth and positively holding the upper baseplate and lower bite rim in proper position during transferral to asimple articulator having a stop.

A particular object of the invention is to provide an improved dentureand procedure of using the same, providing means for improving retentionof the dentures in place during use, particularly in the full lowerdenture.

A still further object of the invention is to provide, in a denture,magnetic core material which is incorporated in the artificial teeth, orin the denture base, for attraction or repulsion of upper and lowerdentures, as the need is determined, to improve retention of thedentures in place during use and to increase the comfort of use thereof.

Still another object of the invention is to provide a method ofconstructing dentures, and a denture constructed in accordance with themethod, in which magnetic material is incorporated in the denture basematerial closely adjacent the mucous membrane of the alveolar ridge toimprove the retention of the dentures, the method and structureincluding the use of magnetic materials, either magnets or magneticmetals implanted in the mucous membrane adjacent the bone, where thealveolar ridges have been absorbed, and the tissue of the ridges builtup with magnetic metals or alloys, in silicone or other suitable filler,to a position which holds the dentures in proper centric and occlusalrelationship and in a firm position in the mouth.

Additional objects and advantages of the invention will be readilyapparent fromthe reading of the following description of apparatus, themethods comprising the invention, and reference to the accompanyingdrawings, wherein:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of a pairof upper front and lower baseplates constructed in accordance with theinvention and showing the magnetic holding and retaining meansincorporated therein for obtaining the proper centric and occlusal planerelationship;

FIG. 2 is a vertical longitudinal sectional view of the baseplates takenon the line 22 of FIG. 3;

FIG. 3 is a transverse vertical sectional view taken on the line 3-3 ofFIG. 1, showing the relationship of the holding means and the bite rims;

FIG. 4 is a transverse sectional view, showing the making of a soft waximpression of the natural jaw movement tracing from the upper finisheddenture on a soft wax impression layer on the lower baseplate bite rim;

FIG. 5 is a fragmentary view similar to FIG. 4 showing a modified formof magnetic bearing used in making a soft was impression or tracing fromthe upper finished denture;

FIG. 6 is an enlarged fragmentary sectional view of a lower jaw showinga lower denture having magnetic retention means incorporated in theteeth, in the denture base material and also under the soft tissue ontop of the alveolar process of the lower jaw;

FIG. 7 is a fragmentary longitudinal sectional view of the lower jaw anddenture of FIG. 6 showing the magnetic retention material with magneticball bearings incorporated longitudinally under the lateral soft tissueor mucous membrane for retention of the lower denture in place;

FIG. 8 is an enlarged fragmentary transverse vertical sectional view,similar to FIG. 6, of an upper and lower denture having magnetic coreretaining means incorporated in the teeth;

FIG. 9 is a fragmentary longitudinal sectional view of a partial dentureor bridgehaving a magnetic retention means incorporated in the bridge ofthe natural teeth and under the soft tissue on top of the alveolarprocess of the jaw; and

FIG. 10 is a top plan view of the device of FIG. 9.

FULL DESCRIPTION OF THE INVENTION In carrying out the practice of themethods or techniques of construction of dentures in accordance with theinvention, an accurate impression of the patients upper and lower ridgesare made in the usual manner. From these impressions upper and lowerstone master models (not shown) are made; then two sets of acrylic orsimilar plastic baseplates baseplates made by vacuum or other suitableprocess on each of the stone models separately to provide two upperplastic base plates 10 and two lower plastic baseplates II,respectively.

On one set of acrylic baseplates, a front wax bite rim 14 section isformed on the anterior portion of the ridge of the upper baseplate,extending to the width of two central incisors and full bite rim 15 isformed on the ridge of the lower baseplate, for use to provide a correctvertical bite relationship of the upper and lower structures of thepatient, as shown in FIGS. 1 and 2. A second similar set of wax biterims is formed on the second set of plastic baseplates, a full lower waxbite rim 15 on the lower baseplate 11, and only an anterior biterimsection 14 on the upper baseplate l0.

In carrying out the procedure of this invention, magnetic means in usedfor stabilizing the bite rims during the preliminary bite measurementsto prevent tilting of the baseplates, to allow easy jaw movement andprovide for a quick, easy, accurate determination of the patients bite.

As shown in FIG. I, a magnet 20, shown to be a circular disc having aflat lower surface 21, and having a metal case 22 enclosing it andprovided with a planar lower surface 23 extending along and enclosingthe flat lower surface 21 of the disc magnet 20, is secured to by a waxanchor 24 to the anterior palatal portion 25 of the upper denturebaseplate. A flat metal plate 26 is secured by means of a wax anchor 27between the anterior lingual portions 28 and 29 of the lower denturebaseplate ll lying substantially along the upper surface of the full waxbite rim 15 on said lower baseplate, if desired. Of course, the waxanchor 27 may be omitted if desired, the plate 20 being secured to thelower denture baseplate II by the wax bite rims 15. The planar lowersurfaces 23 of the magnet case and the upper surface of the metal plate26 are initially set at the approximate desired vertical biterelationship for the patients mouth and at approximate centric position,as determined by observation of the dentist, so that the magnet case andthe metal plate are strongly attracted together by the magnet andtightly engage each other when the baseplates are in proper verticalrelationship as determined by the dentist.

The magnet 20 with its case 22 engaging the plate 26 will hold the upperbaseplate l0 and lower baseplate 11, with the bite rims thereon, in suchfixed vertical and centric relationship during transfer from the mouthto the stone models mounted in an articulator, so that no luting,stapling, or other securing of the baseplates is required. Thearticulator is thus set to the proper vertical and centric relationshipof the baseplates for the patients mouth in the usual manner.

Anterior upper teeth are then selected by the dentist, preferably thesix upper anterior teeth having a width equal to the width of theoutside of the nose from the ala to the ala plus 5 milimeters, whichwill determine the width of the six upper anterior teeth from the tip ofthe cuspid on one side to the tip of the cuspid on the other side. Whenselecting the teeth they are on a flat plane, but when they are set upon the anterior bite rim, which is curved, the cuspids will lie inapproximately the same vertical plane as the ala of the nose of thepatient. These six anterior upper teeth are so selected that the center,vertical height, curvature, and similar aesthetic features of thedenture will correspond most aesthetically to the patients jaw and face.

The anterior teeth are then waxed to the upper baseplate of the secondset of baseplates, and a patient try-in of the anterior teeth forpatients mouth is made, and the remainder of the upper teeth 28 are setup on the upper baseplate, tried in, and finished in the usual way.

Next, a substantially U-shaped soft wax bite surface or impressionsurface 30 is laid out on the upper surface of the flat metal plate 26overlying the lower wax bite rim 15, as shown in FIG. 4. A thinCellophane or other plastic, preferably substantially U-shaped, filmdivider or separator 31 is then placed on the upper surface of the softwax impression surface 30 on the metal plate, and the upper finisheddenture and lower baseplate 11 having the full bite rim 15, the metalplate 26 and the soft wax impression surface 30 covered by the plasticfilm divider 31 thereon, are placed in the patients mouth to make a softwax plastic covered bite path tracing.

The magnet 20 is secured to the anterior palatal portion of the upperfinished denture in a position permitting a ball bearing 40 (FIG. 4) toride freely on the upper surface of the plate 50 interiorly of theimpression surface 30, supports the baseplates 10 and 11 againstdisplacement or tilting and assures a good unifonn tracing or path beingformed in the soft wax impression surface 30 by the teeth 28 of theupper plate or denture. The plastic divider film 31 prevents the upperteeth 28 from sticking to the soft wax impression surface 30, and makesit quite simple to slide the upper teeth with respect to the soft waximpression surface to obtain a correct functional occlusal planemovement.

During the making of the path, if desired, the antifriction thrustbearing 40 may be disposed in a planar indentation 42 formed in thecentral portion vof a metal plate 126, and the case 22 of the magnet 20will slide uniformly with low friction across the thrust bearing 40 andplanar surface of the indentation 42 in the metal plate 126, rolling onthe plate to reduce the friction and the stress imposed upon the ridgesof the patient during the determining of the path. Or, if desired, amagnet 120 having a central aperture 121 therein and ball bearing 140freely rotatably mounted in said aperture, may be secured by a waxanchor 224 to the anterior palatal portion of the finished upper denturein a position in which the ball hearing will ride freely on the planarsurface of the indentation 42 of the metal plate 126. The plastic filmcovered soft wax impression surfaces 30 are engaged by the teeth 28 ofthe finished upper dentures, and, with the ball bearing and the metalplate, prevent tilting or displacement of the upper denture or lowerbaseplate .11 to assure the forming of a good uniform tracing or path inthe soft wax impression surface.

The soft wax registration formed in the impression surface 43 on themetal plate 26 carried by the lower baseplate 11 is then cooled, and astone path made of such tracing to which the lower teeth are set up oradjusted on the lower baseplate.

The balanced lowers are then completed in the usual manner, and thefinished dentures are replaced on the articu lator to balance out anychanges that have taken place as a result of movement of the teeth,shrinkage of materials, or the like during curing, finishing andconstruction of the dentures.

From the foregoing it will be seen that an improved method ofconstructing dentures has been set forth, wherein magnetic means areutilized to hold the plastic baseplates with the wax rims in properrelationship with respect to each other for transferring without luting,stapling, or otherwise fixing the baseplates together for transfer. Itwill also be seen that the magnetic materials provide a base forassuring that the baseplates remain in an untilted relationship in themouth of the patient for the magnetic transfer of the proper occlusalplane and centric relationship, and that many errors normally resultingfrom previous methods have been eliminated.

To assure retention of dentures, especially the full lower denture, lhave devised and made artificial teeth and dentures containing magnets,magnetic powder, or granular alloy magnetic materials, and combinationsof magnets and magnetic materials. These magnetic materials are alsoused in the denture base material and have, in some cases, been imbeddedin the tissue under the mucous membrane along the flabby ridges of thealveolar process, and into the' bone. Such dentures, teeth and magneticmaterial implanted or embedded under the mucous membrane of the patientto provide for magnetic retention of the full lower denture, and of abridge, are shown in FIGS. 6 through 10.

As shown in FIGS. 6 and 7, a lower denture 111 is set to th patientsalveolar ridge; and an elongate metallic stainless steel bar, rod orwire 65, shown in section in FIG. 6, or a plurality of metallic ballbearing spheres 66, shown in dotted lines in FIG. 7, are embedded in thesoft tissue 62 above the bony ridges 63 of the process. Ifdesired, therod or bar 65 or the ball or balls 66 may be embedded in a body ofsilicone filler injected beneath the mucous membrane above the bonyridge to fill the flabby tissue and provide a support and retainer forthe metal inserts. Further, the silicone may be filled with magneticmetal alloy powder or particles, or a magnetic metal wire or rod ormagnets may be placed beneath the mucous membrane as indicated in FIG. 6just between the bone and the mucous membrane by making a small openingin the mucous membrane above the center of the ridge in the cuspid area.The tissue is then freed from distal of the cuspids to distal of thefirst or second molars just enough for the wire or rod, or the balls, orsilicone with the magnetic powder or particles or magnets, to beinserted. For full lower dentures, this treatment is made to both theright and the left sides of the lower jaw along the center of theridges. The balls, rods, magnets, or wires may 'be magnetized and may beenclosed in the silicone material 67 when the ridges require building upto replace absorbed bone. Also, if desired, the metal balls, wire or rodmay be nonmagnetized, but magnetically attractable, so that anartificial tooth 70 having a magnetic metal core 71, a magnetized wire81, or magnetic powder or particles or the like, 80, incorporated in theplastic material of the baseplate 211 of the lower denture will beattracted to the wire and hold the lower denture in place.

As shown in FIG. 6, the lower artificial teeth 70 may be formed withmagnetized metal cores 71, which may be a powder or fine particles ofmetal, or the core may be a small body of metal having a high-magneticcapacity, which is then coated with plastic or porcelain cover and colorcoatings 72 in the usual manner. This magnetic core 71 of the teeth,together with a corresponding polarity body of powdered magneticmaterial or bar 81 in the baseplate coacts with metal balls 66 or rod 65under the mucous membrane or soft tissue 62 of the alveolar process orwhere the absorbed or shrunken bony ridge has been replaced with asilicone filler having a body of magnetic metal alloy powder orparticles incorporated therein, to draw the lower denture baseplate 111into a magnetically attracted stationary position on the alveolar ridge.

Obviously, as shown in FIG. 8, upper artificial teeth having magneticcores 91 coated with plastic or porcelain cover and color coating 92,may be incorporated in the upper denture baseplate 210, and the magneticcores 91 may be magnetized with a polarity corresponding to the polarityof the cores 71 in the teeth 70 in the lower denture baseplate 211,

whereby the teeth and magnetic materials of the lower denture baseplate211 repel the teeth of the upper denture baseplate, and so assist inseparation of the dentures and maintenance of the dentures in place onthe ridges of the patient.

A magnetic rod or bar 95 may be implanted in a recess in the upper endof the bony ridge of the lower jaw to attract the magnetic material inthe lower baseplate of the lower denture and in the teeth 70, to furtherassist in retention of the lower denture in place.

As shown in FIGS. 9 and 10, the magnetic teeth and magnetic retentionmeans may be utilized to retain a partial denture or bridge in placeagainst displacement during use. The bridge 300 is shown to be for thelower jaw and has artificial teeth 70, which are incorporated in abridge having a metal base 310 provided at its opposite ends withmagnetic metal 311 and 312 respectively which engage in metalcomplementary recesses 321 and 322 in the adjacent or abutting naturalteeth 33] and 332. The recesses provide upwardly facing stops to limitdownward movement of the bridge with respect to the natural teeth. Also,magnetic implants 365, which may be metal balls, a rod or wire, or thelike, can be embedded beneath the mucous membrane in or above the bonyridge. If desired, silicone or other suitable filler 367 may be placedbeneath the mucous membrane containing metal ball bearings above thebone to build up the flabby tissue and to bring the metallic magneticretainer implant means 365 into closer proximity to the magnetic metal310 and teeth 70 of the bridge. Also, magnets 381 and 382 may be inlaidinto the natural teeth adjacent the recesses 321 and 322 to furtherattract and retain the bridge in place.

It will be seen that a means and method for magnetic transfer of denturebaseplates with functional balance has been disclosed, that magneticteeth, magnetic dentures and magnetic bridges having new and improvedmagnetic retaining means not before used has been provided.

The foregoing description of the invention is explanatory only, andchanges in the details of the constructions illustrated may be made bythose skilled in the art, within the scope of the appended claims,without departing from the spirit of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. A method of making dentures including: forming upper and lowerbaseplates; mounting magnetic locking means on each of said baseplatesin substantial centric relation in said baseplates; inserting thebaseplates separately in a patients mouth holding the baseplates spacedfrom each other and then locking them together by means of said magneticlocking means in a position of vertical, centric and equalized contactwith the tissue of the patients ridges determined by the structure ofthe patients chewing mechanism and fitting teeth on the denturebaseplates to conform to the patients chewing mechanism.

2. A method of making dentures including: forming upper and lowerbaseplates; mounting a first magnetic member on one of said baseplatesat a substantially centric position; mounting asecond magnetic member onthe other of said baseplates at a substantial centric position to coactwith said first magnetic member to positively hold said baseplatesspaced from each other and locked together by means of said magneticmembers in a position determined by the structure of the patientschewing mechanism; holding said baseplates a position spaced from eachother and locked together position by means of said magnetic members;determining a plane of occlusion for the patient between the baseplates;and fitting teeth on the denture bases to conform to the plane ofocclusion and the relationship of the baseplates as held by saidmagnetic members.

3. A method of making dentures including: forming upper and lowerbaseplates, forming a wax bite rim on only the lower baseplate mountingmagnetic locking means on each of said baseplates in substantiallycentric relation in said baseplates;

disposing the baseplates with the magnetic locking means thereon in thepatients mouth and closing the patient s chewing mechanism to the propercentric and vertical occlusal relationship determined by the structureof the patients chewing mechanism; and locking said baseplates in suchposition by means of said magnetic locking means on said baseplates.

4. The method of claim 1 wherein the molar teeth on the lower baseplateare formed of magnetic material and the molar teeth on the upperbaseplate are formed of magnetic material of like polarity whereby theteeth on the respective baseplates repel each other to bias thebaseplate toward their respective alveolar ridges.

5. A method of the character set forth in claim 3 including the stepsof: fitting teeth on one of said denture baseplates to substantially theocclusal plane of the patient in conformity with the patients chewingmechanism; building a bite rim on the other of said baseplates; buildinga soft wax bite surface or tracing surface on the bite surface of saidbite rim; covering said soft wax surface with a thin nonadhesiveprotective film on the exposed surface of said soft wax surface; fittingsaid baseplate having the teeth thereon and the baseplate having thebite rim with the soft surface thereon in the patients mouth and movingthe patients jaw to define with the teeth an occlusal plane tracing inthe soft wax beneath the film on the bite surface of the bite rim on theother baseplate; and then forming a hard stone mold of the tracingformed in the soft wax surface.

1. A method of making dentures including: forming upper and lowerbaseplates; mounting magnetic locking means on each of said baseplatesin substantial centric relation in said baseplates; inserting thebaseplates separately in a patient''s mouth holding the baseplatesspaced from each other and then locking them together by means of saidmagnetic locking means in a position of vertical, centric and equalizedcontact with the tissue of the patient''s ridges determined by thestructure of the patient''s chewing mechanism and fitting teeth on thedenture baseplates to conform to the patient''s chewing mechanism.
 2. Amethod of making dentures including: forming upper and lower baseplates;mounting a first magnetic member on one of said baseplates at asubstantially centric position; mounting a second magnetic member on theother of said baseplates at a substantial centric position to coact withsaid first magnetic member to positively hold said baseplates spacedfrom each other and locked together by means of said magnetic members ina position determined by the structure of the patient''s chewingmechanism; holding said baseplates a position spaced from each other andlocked together position by means of said magnetic members; determininga plane of occlusion for the patient between the baseplates; and fittingteeth on the denture bases to conform to the plane of occlusion and therelationship of the baseplates as held by said magnetic members.
 3. Amethod of making dentures including: forming upper and lower baseplates,forming a wax bite rim on only the lower baseplate mounting magneticlocking means on each of said baseplates in substantially centricrelation in said baseplates; disposing the baseplates with the magneticlocking means thereon in the patient''s mouth and closing the patient''schewing mechanism to the proper centric and vertical occlusalrelationship determined by the structure of the patient''s chewingmechanism; and locking said baseplates in such position by means of saidmagnetic locking means on said baseplates.
 4. The method of claim 1wherein the molar teeth on the lower baseplate are formed of magneticmaterial and the molar teeth on the upper baseplate are formed ofmagnetic material of like polarity whereby the teeth on the respectivebaseplates repel each other to bias the baseplate toward theirrespective alveolar ridges.
 5. A method of the character set forth inclaim 3 including the steps of: fitting teeth on one of said denturebaseplates to substantially the occlusal plane of the patient inconformity with the patient''s chewing mechanism; building a bite rim onthe other of said baseplates; building a soft wax bite surface ortracing surface on the bite surface of said bite rim; covering said softwax surface with a thin nonadhesive protective film on the exposedsurface of said soft wax surface; fitting said baseplate having theteeth thereon and the baseplate having the bite rim with the softsurface thereon in the patient''s mouth and moving the patient''s jaw todefine with the teeth an occlusal plane tracing in the soft wax beneaththe film on the bite surface of the bite rim on the other baseplate; andthen forming a hard stone mold of the tracing formed in the soft waxsurface.